2003 Voyager transmission problem

My wife drives a 2003 Chrysler Voyager - 3.3L engine. The past month or so the transmission has been intermittantly hard downshifting when slowing down to a stop. Back in April, she was driving it from Tennessee to Georgia and the speedometer dropped to 0 while going about 70. She slowed a bit and it returned to normal. It did this once more a week or so later but not since. She just called me and said that now the car will not go over 45 mph. When I pulled the codes, there were none. The two questions I have are this:

1: Will changing the transmission fluid and filter solve this? The car has about 126,000 miles on it.
2: I did a search and a few search hits came back with a PCM problem. (Ack expensive)

I await any suggestions.

Neal

Does it sound like its in second gear. Really high RPM's at 45MPH? Is the speedo working? I know you said there where no codes but is the check engine light on and did you check for transmission codes are do you just have an OBDII code reader.

Shifting feels like from 3rd to second but not at 45 - usually around 25 to 30. Speedo is working and after the second drop to 0, has not dropped since. I have a homemade OBD but have not tried it on the Voyager yet. The connector on the car has both the ISO-9141 AND J1850 VPW connections. The adapter I have is for 9141 only (optoisolator version). I also have the 1850 PWM unit (Ford) but no longer have a vehicle to use it on (stepson sold his Mercury Cougar). Guess I need to invest in a real OBD unit that will do all the formats. Hopefully the car will still be hot when I get off work so I can recheck the fluid.

Neal

an OBDII code reader will not scan the Transmission control module for codes. If there are codes the trans will let the PCM know and the PCM usually sets a p1171 trans error code (or something simular I can't remember the exact code number right know).

No codes in the PCM - doing the key on/off three times trick about 15 min ago. Checked fluid level - hot & engine running - it may need a little since it was just above the third hole from the tip of the dipstick - a little above the lower edge of the hot region. It also was clear and did not smell burnt. Will get some Sunday and a tranny filter kit to change Monday. Looks like there isn't going to be much rest for me on my one day off this week. :|